Role of Intrinsic Atomic Features and Bonding Motifs from the Surface to the Deep Core on Multistate Emissive Properties of N, B-Co Doped Carbon Dots

Controlling the fundamental photophysical properties of heteroatom-doped luminescent carbon dot has become a challenge due to the lack of fundamental understanding of the correlation between structural and optical properties. Here, we have synthesized green emissive nitrogen (N) doped and intense blue emissive nitrogen, boron (N-B) co-doped carbon dots by a typical one step microwave irradiation technique. To unveil the correlation between their intricate structural features and tunable emissive properties, we have carried out steady state and time resolved optical spectroscopy experiments as well as X-ray photoelectron spectroscopy (XPS) and synchrotron Near K-edge X-ray Absorption Fine Structure (NEXAFS) measurements. We have observed the formation of a specific green emissive molecular domain on the surface of N doped carbon dots and that is almost absent in case of N-B co-doped sample. Although the core domains of both the systems remain aromatic, their intrinsic atomic compositions and structures wer...